FREEZING INJURY TO POTATOES WHEN UNDERCOOLED. 
Russet Rural, and Green Mountain. They were all held at 40° F. 
previous to experimental use. 
Storage tests on the seven varieties held at temperatures below the 
true freezing points were conducted in order to correlate, if possible, 
the freezing points (Table I) of these varieties as determined by the 
thermoelectric method described by Wright and Harvey (9) and the 
actual freezing of the different varieties in storage. These tests were 
conducted at 28° and 25° F. The higher temperature was chosen 
because it represented about the minimum degree of undercooling to 
which the potatoes could be subjected, since it was just below the 
freezing points of most of the varieties used. The lower tempera- 
ture was chosen because it was far enough below the freezing points 
of all varieties to represent a definite degree of undercooling at which 
freezing quickly follows a very light inoculation. When the potatoes 
were selected for the freezing tests they were placed in small wooden 
baskets holding from 8 to 10 specimens, in order that they might cool 
down without much delay. At the conclusion of each test the potatoes 
were removed, to be held at ordinary room temperature for about 24 
hours before being cut longitudinally for examination. If cut imme- 
diately after being removed from storage, no evidence of freezing 
injury will be apparent unless they have been frozen solid. Unless 
specially noted, all injury reported is of the vascular type, as de- 
scribed by Jones, Miller, and Bailey. 
Table I. — Freezing points of seven varieties of potatoes. 
Variety. 
Freezing 
point. 
Variety. 
Freezing 
point. 
Triumph 
°F. 
29.04 
29.66 
29.33 
29.64 
°F. 
28.70 
Irish Cobbler 
Russet Rural 
28.32 
28.50 
American Giant 
Tables II and III show the results obtained from these tests at 28° 
and 25° F. The data presented in Table II show that potatoes did 
not freeze to any serious extent when exposed to 28° F. for many 
hours. In experiment No. 1 two specimens of each variety were held 
seven hours, one specimen of Rural New Yorker being injured. In 
experiment No. 2 twenty specimens of each variety were held 24 hours. 
Onty two varieties showed injury. These included two specimens of 
Irish Cobbler and one specimen of the American Giant. In the third 
experiment two specimens of each variety were held 48 hours, one 
Rural New Yorker being injured. In experiment No. 4 half -bushel 
lots of Triumph, Spaulding No. 4, American Giant, and Russet Rural 
varieties were held in bags for 48 hours with no injury. In experi- 
ment No. 5 eleven specimens of each variety were held for TO hours. 
